In 1910, four gold prospectors summited North America’s tallest mountain in a single day, using little more than donuts and rudimentary equipment. But were they telling the truth?

April 1910. High above their diggings in the mining district of Kantishna, three Alaskan prospectors stopped to catch their breath in the thin, subzero air of America’s highest peak. They had launched the most outrageous and difficult ascent in the early annals of mountaineering.

They knew that their leader, Tom Lloyd, had boasted up a storm back in Fairbanks that got them here. But while worried about how his storytelling might cloud their achievement, there was no stopping now. They’d spent the whole winter preparing. They were going up.